Factorial Java Program using Recursion

Program Description

Write a java program to compute factorial of given number n using Recursion.

IPO Chart

Input

We will take input from the user for n

Process

For n>= 0 , we will do a recursive call using the below formula

fact(n) = n* fact(n-1)

Output

factorial of n.

Java Program

package recursion;

import java.util.Scanner;

/**************************************************
 * FactorialRecursion.java
 * @program : Factorial Using Recursion
 * @web : www.TestingDocs.com
 * @author : 
 * @version : 
 **************************************************/
public class FactorialRecursion {
 //Main method
 public static void main(String[] args) {
 int n;
 Scanner input = new Scanner(System.in);
 System.out.println("Enter positive n:= ");
 n = input.nextInt();

 if(n >= 0)
 System.out.println("Factorial of " + n + " is = " + factRecurFun(n));
 else
 System.out.println("Enter valid input.");
 }

 /**************************************************
 * factRecurFun() is a recursive method to compute
 * factorial of the given number.
 **************************************************/
 public static int factRecurFun(int n) {
 // base case
 if(n < 1 ) 
 return 1;
 else
 //Recursive call
 return n*factRecurFun(n-1);
 }
}